Eureka Valley Sand Dunes and Death Valley (USA, CA) December 2013. Photographer Bob Grieser hikes up a huge Sand Dune. The Eureka Valley Sand Dunes are located in the southern part of Eureka Valley, in northern Inyo County in eastern California, in the southwestern United States. Although covering an area of only 3 square miles (8 km?), the dunes rise approximately 680 feet (207 m) above the surrounding valley floor, making them one of the highest dune fields in North America.Eureka Valley is a